Effect of structural changes on dielectric properties of gallium arsenide

Abstract

Temperature and frequency dependence of dielectric permittivity ɛ′ and tangent of the dielectric loss angle are studied in epitaxial gallium arsenide structures. It is shown that nonmonotonic change in ɛ′ with temperature is caused by change in the volume of conductive gallium microinclusions and a difference between the structural perfection of the layer and substrate. The space charge relaxation time on inhomogeneities is evaluated (τ∼10−5−10−6 sec) and its contribution to GaAs dielectric properties is evaluated. An oscillation in dielectric permittivity upon heating is observed and explained.